yes its bad bro. I dono which sites you're talking about but above article (or what google calls below the fold) is against their Tos. The other sites might be huge providers which google loves and will never ban. Like ladbible or BBC .... etc.. i;ve seen those sites break adsense tos and policy but obviously adsense is not gonna ban BBC. To be specific they are called double doubleclick (DFP).